Caul plate envelope



Nov. 4, 1958 J. H. ODONNELL 2,353,850

I CAUL PLATE ENVELOPE I Filed June 20, 1955. 2 Sheets-Sheet 1 0000 oeoe woeeeoo INVFNTOR. JACK H. ODONNELL j rywaww A TTORNEVS Nov. 4, 1958 J. H. O'DONNELL CAUL PLATE ENVELOPE 2 Sheets-Sheet 2 Filed June 20, 1955 INVENTOR. JACKH. O'DONNELL A TTORNEVS United States Patent CAUL PLATE ENVELOPE Jack H. ODonnell, Seattle, Wash.

Application June 20, 1955, Serial No. 516,547

8 Claims. (Cl. 144-281) This invention relates to a platen press of the type used for forming sheets of plywood or the like, and more particularly to a caul plate envelope structure for platens in such press.

Platen presses used for forming plywood or the like are of a construction which provides for the adhesive securing of sheets of wood between a plurality of overlying and spaced apart platens. By applying pressure and heat simultaneously to such platens, laminated plywood sheets or the like are formed. In order to provide a smooth surface finish on the material and to protect the platens, loose caul plates have heretofore been inserted between the platens and the surfaces of the material. These caul plates which are highly polished, relatively thin metal sheets formed of materials, such as stainless steel, chromium plated steel, aluminum or the like, have proven difiicult to handle because of their weight and siZe, and have required considerable time, labor and material for interleaving with the platens of a press during an operating cycle in the manufacture of plywood or the like.

The present invention avoids the above mentioned disadvantages by providing a caul plate structure for a platen, which eliminates previously required storage space for individual caul plates, obviates much of the heretofore required handling, and improves the quality of the products produced. The invention further presents, among its many features, a simple, economical platen envelope structure for the eflicacious production of plywood or the like.

Summarizing the present invention, it comprises an envelope for a press platen, including a pair of caul plates which engage the opposite pressure surfaces of such platen. A plurality of such enveloped platens is adapted to be supported in overlying relation in the usual manner, in any type of platen press.

It is to be understood that various changes can be made in the arrangement, form and construction of the structure disclosed without departing from the scope or spirit of the present invention.

Referring to the drawings:

Fig. 1 is an isometric view of a corner portion of a typical platen press which incorporates the enveloped platen structure of this invention;

Fig. 2 is an isometric view of one of the enveloped platens in the press of Fig. 1, the parts of the structure being shown in disassembled position for purposes of clarity, and some of the take-up blocks being omitted from the view for the same reason.

Fig. 3 is an isometric assembled view of the platen of Fig. 2;

Fig. 4 is a fragmentary enlarged isometric view of a corner of the platen of Fig. 3;

Fig. 5 is an isometric view from another angle of the platen of Fig. 3, disclosing more clearly a wedge shaped edge of the envelope structure;

Fig. 6 is an end view of a modified platen envelope structure.

Referring to Fig. 1, a plurality of platen members each designatedgenerally by the reference numeral 2 is shown mounted, and supported in overlying relationship in atypical steam platen press, such as that disclosed in Patent No. 2,500,791, dated March 14, 1950.

To maintain platens 2 in overlying vertical alignment, the platens have ring structures 6 aflixed to the corners of each platen, the rings of overlying corners beingslidable on an adjacent tension column 7. Ring structures 6 like those described in the aforementioned patent, are supported by lugs 8 adjustably positioned on column '9 of the platen press in a known manner. It is to be understood that other types of supporting structures also known in the art can be used to support platens 2 in such spaced, overlying relationship. Also, steam is supplied to the hollow interior of the platens in any conventional manner employed in the art, such as by hoses.

With reference to Figs. 2-5, each platen 2 comprises the usual hollow main platen body 11 of suitable metal, and has a fitting 11 to which .a flexible steam line (not shown) is attached in operation. A caul envelope is removably mounted on the platen body, and includes upper and lower caul plates 12 .of the usual highly polished relatively thin metal sheets previously :rnent-ioned; each plate engaging a pressure surface of main body. 11. At one end, each plate 132 is bent or pressed toward the other to provide inclined edge portions 13 secured together at their front .edges by any suitable means, such as by welding, bolting, rivetingwor the like to forma wedge shaped front edge of the envelope. This wedge shape is desirable, since it provides a slide to guide insertion of the work, and thus minimize the possibility :of unsecured sheets from catchingwon the platen as the sheets are slid into the press during a manufacturing :cy'cle.

The space between the front edge of the platen body 11 and the inclined front edges 13 :of the caul plates-il2 can be either filled or open. 'In the embodiment of the invention disclosed, the space is open, and reenliorcing brackets 14 are provided; the brackets beingsecured -in any suitable manner, such as welding, to the inner surfaces of the inclined f'r-ont edges 13 of the-caul plates. When the caul envelope is slipped onto'platen body 11 and secured by the take-up means described hereinafter, brackets 14 bear some of the pressure created by the take-up means, and also serve as stops to prevent the wedge-shaped front edge from creeping up the edge of platen body 11, thus holding the front edges 13 of plates 12 in substantially fixed position relative to the adjacent end of platen body 11. H v

To secure tightly the caul envelopet-o the platen body 11 once it has been slipped thereon and to prevent sag of the lower caul plate 12 which is carried by the upper caul plate, take up means is employed which is cooperable with the rear pair of corresponding edges of caul plates 12 and with main body 11. At the rear, caul plates 12 are each bent or pressed inwardly toward each other at right angles to form spaced apart flanges 16. Each flange 16 is provided with a plurality of spaced apart keyhole slots 17; the slots of the respective flanges being vertically aligned.

Heads 18 of screws secured in removably mounted take-up blocks 19 are adapted to pass through the wide portions of slots 17, and engage the outer surfaces of flanges 16 when extending through the narrow portions of the slots after the take-up blocks are positioned between the rear end of platen body 11 and flanges 16. Take-up blocks 19, in turn, are provided with screws 21 which when screwed tightly against the rear end of platen body 11, force the blocks out against flanges 16 to effect a flat, tight but removable securing of the caul envelope on the platen body. I

It is not necessary to remove the platen bodies from a press to install the caul envelopes, and no changes of any kind are necessary in the original design or operation of I the press in order to incorporate the caul envelopes. The

sides of each envelop e between the front and rear edges are unobstructed. Hence, the two caul plates 12 making up a caul envelope can be easily slipped sidewise over a platen body 11 with a minimum of handling; and the take-up blocks 19 can be quickly positioned in place and tightened, thereby tightly securing the caul plates 12 in place over the opposite pressure surfaces of the platen ..body. In this connection, it will be noted that the rear edges of the caul plates are not originally fixedly secured ,together, but can readily spread apart, thus facilitating installation, and removal for replacement. stalled, the caul envelope can remain on the platen body as a fixed part of the platen, for a large number of cycles of operation over a period of many months. The envelope need only be removed when the caul plates become When inunduly worn.

Fig. 6 of the drawings discloses a modified arrangement for detachably securing the caul envelope onto the platen body. The front edges of caul plates 12 are bent toward each other to form depressed horizontal flanges 22. Overlapping flanges 22 to crimp the same fast, is a wedge shaped crimping plate 23 extending along the front edge of platen body 11. Plate 23 is provided with spaced apart cap screws 24 adapted to screw into tap holes 26.

-19 are moved outwardly by turning screws 21 inwardly,

the caul plates 12 are tightly secured to main platen body 11.

bodies, each envelope including a pair of spaced apart caul plates engaging said pressure surfaces of such body with one of said caul plates of each envelope carried by lthe other caul plate of such envelope, and take up means for securing such removable envelope to the body with which it is associated.

2. A press platen comprising a platen body having I'OPPOSitfi pressure surfaces; and an envelope removably mounted on said platen body including a pair of spaced apart caul plates engaging said pressure surfaces, means adjacent one end of said plates for holding said envelope against an end of said body, and take-up means adjacent the opposite end of said plates for tightly securing said envelope on said body.

"Like the structure of Figs. 2-5, when the take-up blocks 3. A press platen comprising a platen body having opposite pressure surfaces; and an envelope removably mounted on said platen body including a pair of spaced apart caul plates engaging said pressure surfaces, means adjacent one end of said plates for holding said envelope against an end of said body, said envelope at said one end having a wedge shaped slide for work, and take-up means removably mounted adjacent the opposite end of said plates for tightly securing said envelope on said body.

4. The platen of claim 2 in which said take-up means includes blocks removably attached to said plates and screws in said blocks adapted to bear against an end of said platen body.

5. A caul plate envelope for detachable securing on a platen body comprising a pair of opposite caul plates, means adjacent one end of said plates for removably holding them against an end of a platen body, and takeup means removably mounted adjacent the opposite end of sa'idplates for tightly securing said envelope on said body.

6. A caul plate envelope for detachable securing on a platen body comprising a pair of opposite caul plates, means adjacent one end of said plates for removably holding'thern against an end of a platen body, and takeup means removably mounted adjacent the opposite end of said plates for tightly securing said envelope on said body, said plates being capable of being spread apart when said take-up means is removed to facilitate mounting of said envelope on the platen body.

7. A caul plate envelope for detachable securing on a platen body having opposite pressure surfaces, comprising a pair of opposite spaced apart planar caul plates adapted to engage said pressure surfaces, and means for tightly securing said envelope on said body including take-up means adjacent an end of said envelope.

8. A caul plate envelope for detachable securing on a platen body having opposite pressure surfaces, comprising a pair of opposite spaced apart planar caul plates adapted to engage said pressure surfaces, means for tightly securing said envelope on said body including take-up means adjacent an end of said body, and means forming part of said envelope providing a wedge shaped slide for work.

References Cited in the file of this patent UNITED STATES PATENTS 

